2. Back Ground of Related Art
This relates to optical communication systems and finds particular application to optical communication systems for long distance operation or trans-oceanic applications.
Currently a great deal of work is being done on soliton propagation for such above mentioned systems. However, such soliton systems suffer from Gordon-Haus timing jitter. Return-to-zero (RZ) pulses are desired as they are compatible with the all-optical processing technologies envisaged for switching nodes and routing devices.
We have found that RZ pulse propagation may be advantageously employed where the average dispersion is near zero in a single amplifier span, thus reducing the timing jitter, with the use of a saturable absorber to maintain the pulse shape.
According to the present invention there is provided a return-to-zero pulse optical communication system including fast saturable absorber means with propagation near the average dispersion zero wavelength.